Passenger transportation vehicles, such as aircraft, has been exploring implementing the use of fuel cell systems on board. One benefit of the use of fuel cell systems is a cleaner, potentially less expensive, quieter, and more environmentally-friendly source of power. The use of fuel cell systems can supplement energy sources already aboard commercial aircraft. A fuel cell system produces electrical energy as a main product by combining a fuel source of liquid, gaseous, or solid hydrogen with a source of oxygen, such as oxygen in the air, compressed oxygen, or chemical oxygen generation. Fuel cell systems consume hydrogen (H2) and oxygen (O2) to produce electric power. A fuel cell system has several useful by-products output in addition to electrical power. For example, thermal power (heat), water, and oxygen-depleted air (ODA) are produced as by-products. These by-products are far less harmful than CO2 emissions from current aircraft power generation processes. However, these other outputs often are not utilized and therefore become waste.
Moisture-related problems have been reported on commercial or passenger aircraft, including water dripping onto passengers, electrical equipment failures, and wet insulation blankets. All passenger aircraft will experience moisture-related problems in service, but the extent of these problems can vary. Primary sources of moisture may include passenger respiration, operation of humidification systems, air condition condensation, frost accumulation, and potential resulting condensation on the airplane skin. There are skin insulation blankets in service that can help manage moisture-related problems, but improvements are desirable.
Other problems that may exist on-board commercial or other passenger aircraft include cold entry way doors, cold floors, the potential for freezing water lines or water tanks, and other instances in which heated systems may be necessary.